Marine snubber



1962 w H. PLETTA 3,051,448

MARINE SNUBBER Filed May 16, 1960 2 Sheets-Sheet 1 IN VEN TOR.

W. H. PLETTA MARINE SNUBBER Aug. 28, 1962 2 Sheets-Sheet 2 Filed May 16, 1960 llllllllll' lllllllllll |||||l|ll|||l||||| q INV EN TOR.

i m H 0 Q L United States Patent Ofiiice 3,051,448 Patented Aug. 28, 1962 3,051,448 MARINE SNUBBER William H. Pletta, Chicago, Ill. (346 E. Church St., Elmhurst, Ill.)- Filed May 16, 1960, Ser. No. 29,382 13 Claims. (Cl. 254-189) This invention relates to a novel marine snubber construction, and especially a marine snubber for use either on a wharf or on a water craft to hold the water craft in position against the wharf and to move said Water craft as desired along the wharf.

It is found that as a particular vessel is loaded or unloaded, the vessel rises or falls into the water as a result of the loading or unloading. The rise or fall is sufficiently great that the lines holding the vessel tied to a wharf or pier would break unless suflicient slack in the lines were allowed to accommodate the rise and fall of the vessel. In addition to the slack allowed to acommodate the rise or fall of a vessel in water due to unloading or loading, additional slack is usually provided to accommodate changes in water level relative to the wharf or pier caused by tides, seiche, the wake of a passing craft or other such causes. In instances Where there is a great amount of slack allowed in the rope, the vessel has a tendency to shift relative to the wharf or pier. In many operations, such as those involving the loading and unloading of coal barges, for instance, the barges are attached to the pier by a rope having sufficient slack to accommodate most contingencies; however, the barge is not held entirely securely to the wharf or pier so that the wind and current have a tendency to move the barge. Thus, the unloading or loading of the barge is hampered. In such instances of unloading, if the unloading is done with a clam shovel, the clam often drops into the wrong position to properly unload the barge because the barge often shifts as the clam goes down.

Another problem which is appurtenant the use of lines on a wharf is that the wharf owner usually has lines provided for the barges. However, inadvertently these lines may be carried olf by unthinking tugboat operators, so that there is a loss of the lines by the wharf owner and the lines must be replaced. Furthermore, the empty barges must be moved along the wharf as the barges are unloaded so that space may be made for a full barge. Donkey motors and other such devices are used to move the barges; however, they are used only spasmodically and require the starting of the motor for each operation and stopping of the motor after the movement is completed, so that they are not convenient devices for use by the dockhands.

It is one of the objects of the hereindisclosed invention to provide a marine snubber which holds a water craft, such as a barge, against a wharf at all times and during the rise and fall of the craft relative to the wharf due to loading or unloading, tides, seiche or waves.

Another object of the herein disclosed invention is to provide a marine snubber which holds a water craft against a wharf r pier and the lines for attaching the water craft to the wharf or pier are secured to the wharf or pier in such a manner that they may not be carried away on the water craft, or in the alternative, to provide a marine snubber for mounting on a water craft so that the craft has its own lines.

Another object of the hereindisclosed invention is to provide a marine snubber which may be used to move a water craft along a wharf or pier.

Another object of the hereindisclosed invention is to provide a marine snubber from which .a line may be easily attached or removed from a water craft or a wharf by one man without the assistance of a second operator.

Other objects and uses of the hereindisclosed invention will become readily apprarent to those skilled in the 'art upon perusal of the appended specification in light of the drawings, in which:

FIGURE 1 is a cross-sectional view through a wharf or pier showing a barge attached to the pier by a marine snubber embodying the present invention;

FIGURE 2 is a perspective view of a pneumatic cylinder and pulley system used in an embodiment of the present invention;

FIGURE 3 is a cross-sectional view through the marine snubber shown in FIGURE 1, but showing the details of construction more clearly;

FIGURE 4 is a cross-sectional view taken on line 44 of FIGURE 7;

FIGURE 5 is a partial cross-sectional view of a plan view of the marine snubber embodying the present invention shown in FIGURE 1 with a portion of the snubber shown in dotted form to indicate the maximum exten sion of the piston rod which retracts the maximum amount of cable;

FIGURE 6 is a view of a portion of the pulley system embodied in the present invention with the extension of the pulley system shown in dotted form; and

FIGURE 7 is a fragmentary partial cross-sectional view taken on line 77 of FIGURE 5.

Referring now to the drawings and specially to FIG- URE 1, a barge 10 or other similar water craft is attached to a pier or wharf 12 by a wire rope 14 which is connected to a marine snubber 16 generally indicated to be mounted below the deck level of the wharf 12. It is to be appreciated that, although the snubber 16 is shown as being built into the wharf in a generally horizontal position, the snubber may be mounted on the upper surface of the deck proper, or the snubber may be installed in a vertical position.

As may be seen in FIGURE 5, the marine snubber 16, which embodies the present invention, generally includes a fluid motor which is in this instance, a double acting pneumatic cylinder 18, a housing 20 attached to the rod end of the cylinder, a guide frame 22 attached to the housing, a cross head 24 moveably mounted within the guide frame, and a pulley system consisting of several pulleys which will be described in detail below.

The pneumatic cylinder 18 is a conventional double acting pneumatic cylinder which includes a tube 26 having its ends closed by heads 28 and 30. A piston rod 32 extends through head 28 in a conventional manner and is moveable therethrough. An air compresser 34 is connected to both ends of the pneumatic cylinder through a valve 36 which controls the fiow of air to the pneumatic cylinder in a conventional manner.

The housing 20 is secured to head 28 of the pneumatic cylinder. The housing includes a cylinder wall 38 which is fixed to head 28. A longitudinally extending base or floor 40 is secured to the cylinder wall and a pair of sheave walls 42 and 44 are fixed to the floor 40 and to the cylinder wall 38. An apertured end wall 46 is positioned between the sheave walls and on the floor 40 to complete the vertical walls of the housing. A cover 48 is mounted on the upper edges of the four vertical walls to complete the exterior of the housing. The abovementioned piston rod 32 extends through the housing and passes freely therethrough into the guide frame.

The guide frame 22 is secured to the end wall 46 of the housing. The guide frame is also mounted on base 40 which is a channel iron in this instance as may be clear- 1y seen in FIGURES 3 and 4. A pair of side walls 52 and 54 are welded to the base, and the walls 52 and 54 are fixed to the sheave walls 42 and 44 respectively. Mounting plates 56 and 58 are fixed to walls 52 and 54, respectively. A cross plate or cross member 60 is secured to the upper surface of the walls 52 and 54 to brace the walls. A' pair of parallel U-shaped lower rope guides 62 and 64 are mounted on the mounting plates 56 and 58, which rope guides 62 and 64 extend substantially the entire length of the guide frame 22. A second pair of rope guides 66 and 68 are mounted above the first-mentioned pair of rope guides to provide upper rope guides. It is appreciated that the upper rope guides also have a U- shaped cross section, as do the lower rope guides and both pairs of the rope guides have the arms of the U extending toward each other as may be seen in FIGURE 4. A guide rail 70 is mounted on the wall 52 and a second guide rail 72 is mounted on the wall 54. Both of the guide rails are in the same plane and are substantially coextensive with the rope guides mentioned above.

As was mentioned above, the cross head 24 is moveable within the guide frame 22, the cross head is attached to the end of piston rod 32 and the cross head includes a cross head block 74 which has a hole therein which receives the end of the piston rod. A pair of angle irons 76 and 78 are attached to the sides of the block and the angle irons slidingly engage the guide rails 70 and 72, respectively. Strips 80 and 82 having a slightly greater width than the heads of the guide rails are secured to the angle irons 76 and 78, respectively. The strips 80 and 82 have ears 84 and 86 secured to the strips 80 and 82, respectively, which ears 84 and 86 slidingly engage the guide rails 70 and 72, respectively. Thus, the guide rails 70 and 72 have a portion of the rails between the angle iron .76 and strip 82 and angle iron 78 and strip 86, respectively. In this manner, the cross head is supported on the guide rails and the cross head has rail grooves which mate with the guide rails which rail grooves are defined as described above to provide means for guiding the cross head in a straight path. The cross head also has a pulley shaft .88 mounted on the top and a pulley shaft 90 is mounted on the lower surface of the block 74 having the same axis as shaft 88.

An upper moveable sheave 92 is rotatably mounted on the pulley shaft 88 and a lower moveable shaft 94 is mounted on the pulley shaft '90. An upper rope guide tongue 96 is secured to the uppermost portion of shaft 88 and the tongue slidingly engages the sheave 92. A 'U-shaped pair of tongues 97 is attached to the end of the block 74. One arm 98 of the U-shaped tongues engages the lower surface of the upper moveable sheave and the other arm 99 engages the upper surface of the lower moveable sheave. A lower rope guide tongue 100 is attached to the shaft 90 in sliding engagement with the lower surface of the lower moveable sheave. These tongues cooperate in a manner as will be described hereinafter to .guide rope onto the sheaves.

The pulley system has a pair of fixed sheaves in that the fixed sheaves do not move with the cross head. Rather, they simply rotate in position about a substantially fixed center. A horizontal fixed sheave 102 is fixed in a horizontal position in housing 20. An upper sheave support beam 104 is fixed to the sheave walls 42 and 44. A lower sheave beam 110 is mounted on walls 42 and 44 below the .beam 104 and a sheave shaft 112 is mounted between the .beam 104 and beam 110. The horizontal fixed sheave 102 is rotatably mounted on the shaft and the shaft is otfset from the centerline of the rod as may be seen in FIGURE 3.

The pulley system is completed by a vertical fixed sheave 114, which is rotatably mounted on the wall 44. A sheave support ear 116 is secured to the end wall 46 in a conventional manner and a sheave shaft 118 is mounted between the ear 116 and the wall 44. The sheave 114 is moveable along the axis of shaft 118 for reasons which will become apparent hereinafter. The sheave 114 is 4 urged constantly toward wall 44 by a compression spring 119 which is also mounted on the shaft between sheave 114 and ear 116.

The snubber in this instance has a cable tube 120 secured to the wall 44 which wall has an aperture 122 opening into the tube 120. This aperture allows the wire rope 14 to pass through the wall, out through the tube 120 and out through a guide bell 124 which, in this instance, is secured to the side of the wharf. The guide bell 124 reduces the friction between the wire rope and the wharf and provides a means for smooth ingress and egress of the wire rope. It is understood that any other suitable means may be used to provide a smooth ingress and egress of the wire rope. It should be noted that the present construction allows the wire rope to go out freely without any undue wear and the wharf is protected from wear.

The wire rope, which engages all of the sheaves, is secured to wall 42 by an anchor 126 which holds one end of the rope within housing 20. The wire rope extends from anchor 126 into engagement with the upper moveable sheave 92. The wire rope then extends from sheave 92 into engagement with the vertical fixed sheave 114. After the wire rope leaves sheave 114, it engages the lower moveable sheave 94 and the wire rope extends into engagement with the horizontal fixed sheave 102. The free end of the wire rope extends through the tube 120 and out through bell 124. The wire rope has a loop 128 attached to its free end by a swivel-130 which free end is adapted for attachment to a barge or other water craft.

The aforementioned marine snubber 16 operates in the following manner. As was mentioned above it is installed on a wharf or a pier or inside the wharf or pier as shown in FIGURE 1. The wire rope 14 may have its loop 128 held adjacent to the side of the wharf or at the bell 124 by moving the cross head 32 outward to the position shown in dotted form in FIGURES S, 6 and 7. The cross head is moved by applying air under pressure to the appropriate side of the pneumatic cylinder which provides a means for moving the cross head, so that the piston 32 is extended; thereby, pushing the cross head outward and pulling the rope into the snubber. The cross head may be retracted by appropriate control of valve 36, and as long as there is no force on the end of the wire rope, the wire rope stays in position.-

The wire rope stays in position within the rope guides 62, 64, 66, and 68. As may be seen in FIGURE 4, the moveable pulleys 94 and 92 extend within the rope guides 62 and 64, and 66 and 68, respectively. Inasmuch as the two moveable pulleys are of a small size, as soon as the load is taken off the wire the wire has a tendency to spring out into the cable guide. Thus, the cross head may be moved back to a position such as that shown in FIGURES 5 and 6. The wire rope stays within the rope guides ready for use.

When a barge or other water craft approaches the wharf, a single dockhand may grasp the loop 128 on the wire rope and attach the loop to a cleat or other such device on the barge or other water craft. He may easily pull out an appropriate length of wire rope as needed, inasmuch as the wire rope is held freely within the cable guide. After the wire rope is attached to the barge, the snubber is put into operation to hold the barge against the wharf or pier. It should be noted at this point that customarily at least two snubbers are used for each barge.

When the barge is attached to the wire rope, air under pressure is applied to the pneumatic cylinder from the source through valve 36 which valve provides regulating means for controlling the movement of the cylinder. The rod 32 is pushed out of the cylinder pushing with it the cross head 24 in a set longitudinal path. As the cross head moves forward, the sheaves finally engage the loop strands of the wire rope. At this point the rope guide tongues come into effect to provide sheave rope guide means. They engage the wire rope should it be slightly displaced and guide it into the groves of the appropriate sheaves. Thus, the pulley system engages the wire rope. As the cross head 24 is pushed further from the housing 20, the wire rope is pulled in toward the snubber until the barge rests against the side of the wharf or pier. As the barge is unloaded and rises out of the water the snubber takes up the Wire rope which is let out. However, as the barge rises further out of the water and necessary rope is required to allow for the further rise the rising of the barge tends to push the rod back into the cylinder against the force of the air pressure thereby taking more rope as it is needed.

It is understood that the opposite situation may be accommodated by the instant construction; that is, when a barge or other water craft comes in empty, it sinks lower into the water as the craft is loaded.

It may be noted that the operation of the instant snubber is based upon the fact that a much lighter force is required to hold a water craft against a wharf or pier than is the buoyant force of the water craft or the weight of the craft. It is also understood that the instant device may be used with a hydraulic cylinder rather than a pneumatic cylinder such as that described herein.

It may be appreciated how the present device may be used to move the barge from one location to another simply by judicious attachment of the appropriate snubber to the appropriate position on a barge to move it along a wharf or pier.

While a specific embodiment of the instant invention has been shown and described herein, it is expressly understood that those skilled in the art may make various alterations and modifications such as, mounting the snubbers on a water craft or installing the snubbers in a vertical position rather than a horizontal position, and the scope of the invention is limited only by the appended claims.

What is claimed is:

1. A marine snubber for holding water craft against a wharf comprising, in combination, a housing, a frame adjacent to said housing, a pair of elongated rope guides mounted on said frame, a cross head moveable in said frame substantially parallel to said rope guides, a sheave cooperative with each of said rope guides, said sheaves being rotatably mounted on the cross head and moveable therewith, a pair of sheaves rotatably mounted in said housing, a wire rope anchored at one end engageable with the first-mentioned pair of sheaves, said wire rope being in engagement with the second-mentioned pair of sheaves and extractable from said housing, means for moving the cross head to retract the wire rope into the frame and to move the cross head toward the housing, and regulating means for controlling the movement of the first-mentioned means and selectively applying a load to the wire rope, whereby the cross head is moved away from the housing to retract the wire rope, and the cross head is then moved back to a position adjacent to the housing leaving the wire rope in the cable guides for easy extension for attachment to a water craft, then the cross head is moved into engagement with the wire rope to apply a force to hold the water craft against a wharf.

2. A device of the character described comprising, in combination, a wire rope for attachment to a water craft, a pulley system engageable with said wire rope, support means moveably supporting a portion of said pulley system, an elongated cable guide adajacent to the path of the moveable portion of said pulley system for supporting the cable, and means for moving the support means, whereby the wire rope is retained in the cable guide for easy extension when the rope is not attached to a water craft and its support means is retracted, and when the wire rope is attached to a water craft, it is held taut by the means for moving the support means.

3. In a marine snubber having a fluid motor, the improvement comprising, in combination, a wire rope having one end fixed and the other end free for attachment to a water craft, a sheave engageable with the wire rope, said sheave being rotatably connected to the fluid motor to be moved thereby in a straight path, and an elongated sheave rope guide adajacent to the center of the sheave for guiding the wire rope into the sheave, whereby the sheave may be retracted from the wire rope when the rope is free and the sheave rope guide guides the rope into proper engagement with the sheave when the rope and the sheave are moved toward each other.

4. In a marine snubber having a fluid motor, the improvement comprising, in combination, a sheave moveable in a straight fixed path, said sheave being rotatably connected to the fluid motor to be moved thereby, a pair of tongues mounted adjacent to the sheave and moveable therewith, a wvire rope having one end fixed and the other end free for attachment to -a water craft, said wire rope being engageable with the sheave, and an elongated rope guide extending substantially parallel to the path of the sheave, whereby the wire rope is positioned in the rope guide by the sheave and is supported therein when the wire rope is free from attachment to a water craft and the wire rope i guided into proper engagement with the sheave by the tongues when the wire rope is secured to a water craft.

5. A marine snubber comprising, in combination, a frame, a rotatable sheave moveably mounted on said frame for movement in a fixed path, a second rotatable sheave fixedly mounted relative to the first-mentioned sheave, an elongated wire rope engageable with said sheaves, means for selectively moving the first-mentioned sheave to move a section of the wire rope, and a rope guide fixed to the frame adjacent to the path of the first-mentioned sheave for supporting a portion of the wire rope.

6. In a marine snubber having a fluid motor, the improvement comprising, in combination, a sheave moveable in a set longitudinal path, said sheave being connected to the fluid motor to be moved thereby, an elongated rope guide extending substantially parallel to the path of the sheave cooperative with said sheave and being substantially coextensive with the path of the sheave, and a wire rope having one end fixed and the other end free for attachment to a water craft, said wire rope engageable with the sheave during attachment to a water craft and receivable in the rope guide when free from attachment to a water craft.

7. A device of the character described comprising, in combination, a frame, a sheave fixedly mounted relative to the frame, a cross head moveably mounted in said frame, a second sheave mounted on the cross head, a wire rope having one end fixed relative to the frame and the other end free for attachment to a water craft, said wire rope engageable with the sheaves, an elongated rope guide mounted on the frame for receiving and supporting the wire rope, and a cylinder having a piston rod connected to the cross head for moving the cros head relative to the frame to move the free end of the wire rope relative to the frame.

8. In a marine snubber having a fluid motor and a wire rope having one end fixed and the other end free for attachment to a water craft, the improvement comprising, a sheave moveable in a set longitudinal path, said sheave being rotatably connected to the fluid motor to be moved thereby, a sheave rope guide adjacent to the center of rotation of the sheave for guiding the rope into proper engagement with the sheave, and an elongated rope guide extending substantially parallel to the path of the sheave and being substantially coextensive with the longitudinal path of said sheave, whereby the sheave is retractable from the wire rope and the wire rope is supported in the rope guide when the sheave is retracted, and the sheave rope guide guides the rope into proper engagement when the rope and the sheave are moved toward engagement.

9. A marine snubber comprising, in combination, a fluid motor, a frame connected to said fluid motor, a

sheave rotatably connected to the fluid motor and moveable therein in a straight path within said frame, a pair of rope guides mounted on said frame, said rope guides being on opposite sides of the path of said sheave and being substantially parallel to said path, a wire rope having one end fixed and the other end free for attachment to a Water craft, said Wire rope being engageable with the sheave and the rope guides, whereby the wire rope is supportable by the rope guide and the sheave may be retracted toward the fluid motor out of engagement with the wire rope, and the sheave being selectively placed in engagement with the wire rope by movment into engagement.

10. A marine snubber comprising, in combination, a fluid motor, a frame connected to said fluid motor, a pair of substantially parallel rope guides mounted on said frame, a sheave rotatably connected to the fluid motor, said sheave moveable in a path between said rope guides, a rope having one end anchored and the other end free for attachment to a water craft, said rope being engageable with the sheave and being positioned between the rope guides, whereby the sheave is retractable from the rope, and the rope is supported by the rope guides and the sheave is selectively placed into engagement with the rope.

11. A marine snubber comprising, in combination, a fluid motor, a frame connected to said fluid motor, a pair of substantially parallel elongated rope guides mounted on said frame, a sheave rotatably connected to said fluid motor, said sheave being positioned between the rope guides and moveable in a path substantially parallel to the rope guides, a wire rope having one end anchored and the other end free for attachment to a water craft, a portion of said wire rope extendable along a portion of one of said rope guides, and adjacent portions of the rope being looped from the first-mentioned portion, said looped portion being engageable with the sheave and a third portion of the rope integral with the looped portion extendable along the second-mentioned rope guide and engageable therewith, and a sheave rope guide adjacent to the center of the sheave for engaging the looped portion of the rope to guide the looped portion of the rope into proper engagement with the sheave, whereby the sheave is retractable from the looped portion of the rope and the rope is held in position by the rope guides, the sheave is moveable to re-engagement with the looped portion of the rope and the sheave rope guide directs the rope into proper engagement with the sheave.

12. A marine snubber comprising, in combination, a fluid motor, a base connected to said fluid motor, a pair of rope guides substantially parallel to each other mounted on said base, a second pair of rope guides spaced from the first-mentioned pair of rope guides being substantially parallel to each other and to the first-mentioned pair of rope guides mounted on said base, a sheave rotatably connected to the fluid motor positioned between the first-mentioned pair of rope guides, a second sheave rotatably connected to the fluid motor positioned between the second-mentioned pair of rope guides, a third sheave rotatably mounted on said base and having a diameter substantially equal to the distance between the first two-mentioned sheaves, a rope having one end anchored and engageable first with the first-mentioned sheave, then the third-mentioned sheave and then the fourth-mentioned sheave, said rope having its other end free for attachment to a water craft. 7

13. A marine snubber comprising, in combination, a fluid motor, a base connected to the fluid motor, a sheave rotatably connected to the fluid motor, a second sheave rotatably connected to the fluid motor, a third sheave rotatably mounted on said base, said first mentioned and second sheaves connected to the fluid motor being moveable in a substantially straight path, a Wire rope having one end anchored engageable with the first-mentioned sheave, then the third-mentioned sheave and then the second-mentioned sheave, said rope having its other end free for attachment to a water craft, a pair of rope guides engageable with the portion of the rope extending from the fixed end to the first-mentioned sheave, a second rope guide engageable with a portion of the rope extending from the first-mentioned sheave to the thirdmentioned sheave, a third rope guide engageable with the portion of the rope extending from the third-mentioned sheave to the second-mentioned sheave, and a fourth rope guide engageable with a portion of the rope extending from the second-mentioned sheave to a length equal to the other rope guide, said rope guides being connected to the base.

References Cited in the file of this patent UNITED STATES PATENTS 247,680 OHanlon Sept. 27, 1881 158,951 Lane et a1 Jan. 19, 1875 508,221 Hill Nov. 7, 1893 1,862,409 Lamond June 7, 1932 2,500,879 Smallpiece Mar. 14, 1950 2,588,037 Orton Mar. 4, 1952 2,943,886 Wilkinson July 5, 1960 2,952,236 Moyes Sept. 13, 1960 

